Intermittently operating apparatus for making bags



Feb, 26, 1957 Filed Aug. 10, 1953 A. w. RICHENS 2,782,694

INTERMITTENTLY OPERATING APPARATUS FOR MAKING BAGS 3 Sheets-Sheet l INVENTOR.

BY ATTORNEY Feb. 26, 1957 A. w. RICHENS 2,732,694

INTERMITTENTLY OPERATING APPARATUS FOR MAKING BAGS Filed Aug. 10. 1953 3 Sheets-Sheet 2 Ijl i PM y ATTORNEY INVENTOR:

Feb. 26, 1957 A. w. RICHENS 2,782,694

INTERMITTENTLY OPERATING APPARATUS FOR MAKING BAGS Filed Aug. 10, 1953 3 Sheets-Sheet 3 INVENTOR flrlur IV flit/Zens @BL: 2 m Y We.

ATTORNEY United States Patent INTERMITTENTLY OPERATING APPARATUS U FOR MAKING BAGS Arthur W. Richens, Chester County, Pa., assignor to Continental Can Company, Inc., New York, N. Y., a corporation of New- York Application August 10, 1953, Serial No. 373,284

6 Claims. (Cl. 93-22) It is an object of this invention to provide a cheap, simple, compact machine for making bags of the type disclosed in my copending application Serial No. 52,465 filed October 2, 1948, now Patent No. 2,648,263. The bag in question is-a' gusseted bag having a bottom of the automatic type in which the four walls of the bag are gathered centrally of the bottom into an upstanding fin which is subjected to a heat sealing operation to coalesce the walls if the bag be 100 percent film or to adhere to the walls if the bag be lined with film or spot printed within the area of the film with thermoplastic material. Thereafter the sealed film is folded over against the automatic bottom and secured thereto.

It is a further object of this invention to provide a machine of the class aforesaid which will be intermittent in operation, that is, in which spaced consecutive bag lengths. of gusseted tube are simultaneously advanced from one station to the next and in which the bottoming operations are performed during the period of dwell intermediate the periods of advance.

The above and other objects will be made clear from the following detailed description taken in connection with the annexed drawings in which:

Figure 1. is a schematic side elevation of the machine as a whole.. Because of limitation of scale, the operating stations are merely indicated for location.

Figure 2 is a side elevation of a portion of station A taken in the same plane. as Figure l-.

Figure 3 is a front elevation partly in section on the line 33 of'Figure 1.

Figure 4 is a side elevation of the station C.

Figure 5 is a section onthe line 5-5 of Figure 1.

Figure 6 is a top. view taken'on line 66 of Figure 3, and

Figures 7a through 7 are diagrammatic views illustrating the bag bottoming operation carried out in station A of Fig. 1.

In my copending application entitled Continuously Operating Apparatus for Making Bags, Serial No. 373,- 283' filed of even date herewith, I show two forms of machines for making the above described type of bag bottom and doing this continuously and at high speed. The benefits of continuous high speed operation are obvious. and need not be elaborated here. There are, however, certain disadvantages to the high speed continuous units when only small quantitiesv of bags are involved. In the first place, such units are large and costly due to the multiplication of parts and. inevitably are difficult to adjust from one size bag to another. While the high speed machines are operating they produce at low cost but in any stoppages or change overs the idle time is more costly. Consequently for small orders of offstandard bags there. is a very real need for a machine which though slower in operation is far easier to adjust parts making up andmake ready.

In any intermittent bagging operation which involves True enough the perfection of a heat seal depends on the interrelated efiects of time, temperature and pressure, that is, an increase of temperature permits a reduction of time and/or pressure and an increase of time permits a reduction of pressure and/or temperature. In practice, however, both temperature and pressure are subject to well defined limitations. Certainly the temperature may not be made such as to char or decomposev the material being sealed nor may the pressure be raised to a point at which extrusion of the thermoplastic material takes place since extrusion would effect a sharp reduction of caliper and consequently of strength. As a consequence, in a duplex bag in which the temperature gradient of. at least one interface is encountered a time of at least 2 seconds is required within any tolerable limits of temperature and pressure.

Allowing 2 seconds of actual engagement of the heat sealing jaws and /2 second more to complete the cycle and shift the bag to the next station a percent straight line intermittent action allows a maximum theoretical production of 24 bags per minute and in practice such a machine probably would produce about 10,000 bags per 8-hour shift.

Referring now to Figure 1 there is shown a conveyor belt It) supported on a table 12. A pair of sprocket chains 14 (Fig. 5) run parallel to the belt 10 on opposite sides thereof and are engaged by pairs of sprockets 16, each pair driving feed roller 18. Since the chains 14 are completely synchronized with the belt 10 there is a positive feeding of the bag lengths 20 of gusseted tubing between each roll 18 and the belt it). The drive is by means of wheels 22 through a gear 24 which engages a gear 26 on a shaft 28. The shaft 28 is periodically rotated through a one revolution clutch which is periodically tripped by cam means.

The clutch and earns means being purely conventional, are not illustrated.

The spacing and size of the rolls 18 are important. The bag lengths not only are spaced but as will later appear the bag length changes and shortens in the course of the bottoming operation. The rotation of each roll 18 is sufficient to bring about an advance equal to one bag length plus the spacing between bags. Say, for example, that the initial tube length is 11 /2 inches and that the consecutive tube lengths are spaced 1 inch apart along conveyor 10, then the feed must amount to 12% inches. It follows that the spacing between rolls 18 must not be more than 12 /2 inches center-to-center and preferably the spacing is substantially less. This insures that any prior roll 18, coacting with the belt 10, will advance the bag length within its grip into the grip of the next roll 18.

Bag lengths 2e are fed to the machine between a feed roll 30 and the conveyor 16 which passes over a return roll- 32. The tube lengths may be supplied from a magazine (not shown) or may be drawn intermittently from a conventional tubing. In the latter case the cut-off on the tube is synchronized with the conveyor 10 and the feed rolls 18 to bring about a spacing between consecutive bag lengths.

Because the dwell at the heat sealing station hereinafter described is very large (2 seconds) compared with the period of advance and retraction, /2 second) it is possible to combine three different functions at a single initial operating station. This station is indicated at A (Fig. 1) but is not shown in detail because of the exigency of scaling. it is, however, shown in detail in Figs. 2, 3 and 6.

In an intermittent operation of this type it is most desirable that the bottom be thoroughly established at a single station since otherwise residual elasticity of. the paper would tend to destroy the bottom formation between stations and it would be quite impossible to use. the combination of belt and roller 18 for advancing the bags.

. As described in my above-identified copending application Serial No. 373,283 and as shown in Figs. 7a through 7 in establishing a bottom of this type a conventional type flat longitudinally seamed laterally placated tube 20 is fed into station A, where the first step in forming the bag bottom is to rotate one gusset fold line relative to the other to establish an open rectangular boxlike structure with the bottom of the box folded against the body of the bag (see Figs. 7a and 7b). The next two steps are approximately coincident, one having only a slight lead in point of time over the other. The first of these is to indent the sides of the box like structure containing the central gusset fold lines, (see Figs. 7c and 7d) this to be followed by a compression and collapse of the two remaining walls toward each other (see Fig. 7c) the result being to form a flattened bottom having a central upstanding fin (see Fig. 7 If desired, score lines L through 0 (Fig. 7a) may be positioned in the open tube near one end thereof before the bottoming operation to assist in orienting the folds in the bag bottom. An adhesive P for holding the upstanding fin together may also be applied before the bag bottom is formed. Referring to the drawings, it will be seen that in order to form a central upstanding fin across the bottom of the bag it is essential that the paper in the box-like structure be so folded that the height of two opposite side walls of the box are greater than one-half the distance between such side walls. The interior of the bag walls at least within this fin previously have been coated or otherwise prepared so as to present mutually contacting thermoplastic surfaces. On the exterior there is usually applied patches of thermoplastic material within the area of the fin and on the contacting gusset walls. All of this application of thermoplastic is thoroughly described in my aforesaid copending application. These several operations occur at the stage indicated as A in Fig. l and are detailed in Figs. 2 and 3.

The initial gusset rotating operation is carried out by a carriage 34 having guide members 36 riding in grooves in fixed guide plates (not shown). The carriage 34 has secured to it a cylindrical cam follower 38 hearing in a groove in a box cam 40 rotated by a shaft 42. The box cam 40 acts to reciprocate the carriage 34 toward and from the conveyor belt 10 and to give the carriage the appropriate period of dwell at each end of its stroke. On the carriage 34 there are mounted two pairs of forwardly projecting fingers, the fingers 43 of the carriage being rigidly secured thereto and spaced to engage on opposite sides of the lowermost gusset fold. The other pair, visible in Fig. 3, and designated 44, are spaced to receive between them the upper gusset fold. Fingers 44 engage a stub shaft 46 which passes through a bearing 48 to have a friction fit, first with a bafiled pinion 50 and, second, with a spur gear 52. A second baffled pinion 54 is journaled on a stub shaft (not shown) secured in the carriage 34. An arcuate bathed rack 57 is formed on the surface of the box cam 40 for engagement with the bafiled pinion 54 if as shown in Fig. 3 the carriage 34 is in its innermost position.

In the position of Fig. 3 the carriage 34 is in a period of dwell and none of the other parts hereinafter described are in their active position. At this point the rack 57 encounters the baffled pinion 54 and protects the same which has the effect of rotating the baffled pinion 50, hence the shaft 46 and the members 44. These members 44 rotate rearwardly from a position superimposed on the fixed -fingers 43 and thereby rotate the upper gusset of the bag rearwardly relative to the lower gusset. The result as fully described in my aforesaid copending application is to open the leading end of the gusseted tube into a rectangular box like condition with the bottom of the box folded back against the body of the tube (see Figs. 7a and 7b).

The fingers 44 remain in the position indicated in Fig. 3

through a period of dwell. During this period an intucking member 56 pivoted at 58 to an arm 60 is swung from its dotted line position to the full solid line position of Figure 3. The arm 60 swings about a pivot 70 supported in a frame 72 which also supports bosses 74. An arm 76 forms a prolongation of the arm 60 and has at its free end a cam follower 78 bearing on a box cam 80. A similar arm 82 is mounted at the opposite side of the conveyor 10 and a carriage similar to the carriage 34 is also mounted at the opposite side. The arm 82 is under the control of an auxiliary arm 84 having a cam follower 86 bearing on a box cam facing opposite to the cam but not shown. The box cams are rotated by a shaft 88 running above and parallel to the conveyor 10.

A spring 62 connects the arms 60 to the rearwardly projecting end 61 of the member 56 and draws it against a fixed abutment 64 formed on the arm 60. The purpose of this arrangement is to permit the member 56 to be thrust upwardly in order to provide clearance of the fingers 44.

The bosses 74 support a pivot pin 90 on which is pivoted a pair of jaws 92. Each jaw 92 has an arm 94 terminating in a cam follower 96 which is operated by oppositely facing box cams 98. The timing is such that the members 92 approach each other with only a slight time lag after initial inward movement of the members 56 so that all members arrive substantially simultaneously at the extreme inward position indicated in Fig. 3. This completes the collapse of the box like formation into a flattened, automatic type bottom having a central upstanding transverse fin secured between the members 92. It will be noted that in collapsing the box-like structure tucking members 56 so move into the box that the surface of the tucking member which is in contact with the paper moves substantially in a plane which is approximately parallel to the plane of the body of the bag tube and the tucking members are operative for collapsing only the lower portion of the box walls against the body of the bag tube. The top portions of the side walls of the box remain standing substantially upright at the center of the box where such top portions project up above the level of the collapsed box substantially in face-to-face relationship. Jaws 92 thereafter tightly press the projecting top portions of the box together (see Figs. 7d and 7e) to form the central upstanding fin across the bottom of the bag.

At this point the box cam 40 retracts the carriage 34 and brings the pinion 52 into engagement with an annular gear 100 secured to a beveled gear 102 which is pivoted on a fixed shaft 104. An arcuate beveled rack 106 is formed on the upper surface of the box cam 40 to rotate therewith. When the pinion 52 engages the annular gear 100 the rack 106 engages the beveled gear 102 rotating the same and thereby restoring members 44 to their original position. It is to be noted that the rack 57 though rotating in the same direction as the rack 106 has the effect of rotating the shaft 46 and therefore members 44 in a direction opposite to that obtained by the action of rack 106 on gear 102.

The members 56, viewed in plan, taper to an apexat their free ends, the taper being at 45 degrees to conform to the ultimate folds which the member 56 helps to establish. The under side of such bars, as set forth in my copending application of even date herewith, are insulated to shield the bottom of the bag against any possibility of blocking.

From station A rolls 18 and belt 10 advance the bag to station B. This station has not been illustrated in detail because, structurally, it is identical with the members 92, 90, 94, 96 and 98 of Fig. 2 with the exception that the members 92 are replaced by bars containing heating elements as is conventional in heat sealing practice.

From station B another set of rolls 18 advance the bag to station C which is detailed in Fig. 4. Rolls 18 naturally fold flat the formerly upstanding fin which, however, re- ,tains sutficient residual elasticity to rise slightly from the body of the bag after it arrives at station C. At this station there is provided a fixed frame member 110 having formed thereon a boss 112 to which is pivoted a guide member 114. The guide member 114 has a depending arm 116 biased by a spring 118 to the fixed member 110. A rod 120 is slideably mounted in the guide member 114 and has at its upper end a cam follower 122 operated cyclically by a box cam 124 secured to the over-head shaft 88. At its lower end the rod 120 has affixed a plate member 126 which is the full Width of the conveyor 10. During most of the cycle the rod 120 and blade 126 occupy the position shown in full lines in Fig. 4. A paste vat 128 contains a roll 130 which bears on a transfer roll 132 which in turn bears on an applicator roll 134.

When a bag X arrives at station C the cam 124 raises the rod 120 to bring the blade 126 into momentary contact with the applicator roll 134 which coats the extremity of the blade with paste. The cam 124 then lowers the rod 120 toward the bag X. A roller 136 journalled in a boss 138 on the rod 120 then encounters a cam surface 140 on the frame member 110. This thrusts forward the rod 120 to engage the blade 126 with the fin 9 on the bag X, coating the same with paste. Thereafter the cam 124 raises the rod 120 and its associated pans back to the intermediate full line position of Fig. 4.

On the next advance of the bag X the final set of rolls 18 act to fold the fin 9 against the bag bottom and the bag is completed and discharged over the forward roll 22.

What is claimed is:

1. Apparatus for making bags comprising means to advance a series of spaced bag lengths, said advancing means operating intermittently, means operative during a dwell in the advance for gripping a bag length of flattened gusseted tube near an open end thereof, said means also being operative to open such end of said tube to form an open rectangular box having its bottom in the flattened body of the tube, tucking means operable during the dwell in said advance for collapsing said box-like structure against the body of the bag to leave an upstanding fin running across the tube, additional means operative during the dwell in said advance for subjecting said upstanding fin to heat and pressure and other means for folding and pasting said upstanding fin against the body of the bag.

2. Apparatus according to claim 1 in which said collapsing means comprise three sequentially operated units at a single station.

3. Apparatus according to claim 1 in which the advancing means is positive in operation.

4. Apparatus according to claim 3 in which said collapsing means comprise three sequentially operated units at a single station.

5. Apparatus for making bags comprising means to advance a series of spaced bag lengths, said advancing means operating intermittently, means operative during a dwell in the advance for gripping a bag length of gusseted tube and for opening one end of said tube to form an open box therein, in which two opposite side walls of the box have a height greater than one-half the distance between such side walls tucking members operable during the dwell in said advance for collapsing said box-like structure against the body of the bag means for mounting said tucking members adapted to move the surface of the tucking members which contacts the paper substantially in a plane parallel to the plane of the body of the bag tube to bring together top portions of the aforesaid opposite side Walls at the center of the box where such top portions project up above the level of the collapsed box and pressure means operative during the dwell to press the projecting top portions together and form an upstanding fin running across the box to close the open box and form a bottom for the bag.

6. Apparatus for making bags comprising means to advance a series of spaced bag lengths, said advancing means operating intermittently, means operative during a dwell in the advance adapted for gripping one end of a bag length of gusseted tube and for opening such end of the tube to form an open box therein, in which two opposite side Walls of the box have a height greater than one-half the distance between such side walls, tucking members operable during the dwell in said advance for collapsing the lower portion of said box-like structure against the body of the bag, means for mounting said tucking members adapted to move said members in against the paper in the lower portion of opposite side walls of said box-like structure to collapse the lower portion of the box and bring together top portions of the aforesaid opposite side walls at the center of the box where such top portions project up above the level of the collapsed box and pressure means for pressing the projecting top portions together to form an upstanding fin running across the box to close the open box and form a bottom for the bag.

References Cited in the file of this patent UNITED STATES PATENTS 331,722 Lorenz Dec. 1, 1885 687,679 Eisenbeis Nov. 26, 1901 2,349,732 Howard May 23, 1944 2,353,402 Haslacher July 11, 1944 2,412,501 Gardner Dec. 10, 1946 

